From: Carl Worth <cworth@cworth.org>
Date: Wed, 12 Jun 2013 23:16:51 +0000 (-0700)
Subject: dlwrap: Don't resolve libfips_handle on every call to dlopen.
X-Git-Url: https://git.cworth.org/git?p=fips;a=commitdiff_plain;h=54157251d30d586e8f97fb594f22bf18e9ac4bbe

dlwrap: Don't resolve libfips_handle on every call to dlopen.

Instead, call dladdr and the real dlopen on the first call to dlopen
then save the libfips_handle result for all future calls.
---

diff --git a/dlwrap.c b/dlwrap.c
index aac06f6..9f623da 100644
--- a/dlwrap.c
+++ b/dlwrap.c
@@ -46,17 +46,23 @@ dlopen (const char *filename, int flag)
 	if (STRNCMP_LITERAL (filename, "libGL.so"))
 		return dlwrap_real_dlopen (filename, flag);
 
-	/* Redirect all dlopens to libGL to our own wrapper library.
-	 * We find our own filename by looking up this very function
-	 * (that is, this "dlopen"), with dladdr).*/
-	if (dladdr (dlopen, &info)) {
-		libfips_handle = dlwrap_real_dlopen (info.dli_fname, flag);
+	/* Otherwise, for all libGL lookups we redirectl dlopens to
+	 * our own library. If we've resolved libfips_handle before,
+	 * our work is done. */
+	if (libfips_handle)
 		return libfips_handle;
-	} else {
+
+	/* We find our own filename by looking up this very function
+	 * (that is, this "dlopen"), with dladdr).*/
+	if (dladdr (dlopen, &info) == 0) {
 		fprintf (stderr, "Error: Failed to redirect dlopen of %s:\n",
 			 filename);
 		exit (1);
 	}
+
+	libfips_handle = dlwrap_real_dlopen (info.dli_fname, flag);
+
+	return libfips_handle;
 }
 
 void *